Simulation of MHD CuO–water nanofluid flow and convective heat transfer considering Lorentz forces

Magnetic nanofluids (MNF) constitute a special class of nanofluids that exhibit both magnetic and fluid properties The interests in the use of MNF as a heat transfer medium stem from a possibility of controlling its flow and heat transfer process via an external magnetic field This review presents recent developments in this field with the aim of identifying major affecting parameters and some novel applications This review emphasizes on thermal conductivity enhancement and thermomagnetic convection in devices using MNFs as heat transfer media

Heat transfer enhancement by magnetic nanofluids—A review

Effects of MHD on Cu–water nanofluid flow and heat transfer by means of CVFEM

Flow and heat transfer characteristics of magnetic nanofluids: A review

The objective of this paper is to review the different techniques, which have been used to enhance the heat transfer rate in heat exchanger devices such as solar air heater, cooling blades of turbine and so on using single phase heat transfer fluids. The results of recent published articles with the development of new technologies such as Electrohydrodynamic (EHD) and Magnetohydrodynamics (MHD) are also included. Enhancement of heat transfer in heat exchanger can achieved by means of several techniques. These techniques are grouped into the active and passive method. In the active methods, system need some external power, however, passive method utilize surface modification either on heated surface or insertion of swirl devices in the flow field. Active methods are very complex because of external power supply, although these methods have great potential and can control thermally. Passive methods include artificial roughness, extended surface, winglets, insertion of swirl devices in the flow which alters the flow pattern causes to disturb the thermal boundary layer, and consequently high heat transfer. Passive methods are dominant over active methods because its can easily employed in existing heat exchangers. In this paper, an effort has been made to categorize the active and passive methods and review the various heat transfer techniques applied in heat exchangers. Important results have been listed for ready reference. It has been concluded that either active or passive methods have been employed alone. Based on literature, a combined method have also been recommended which include both active and passive methods.

A comprehensive review on single phase heat transfer enhancement techniques in heat exchanger applications

Numerical study of the ferrofluid flow and heat transfer through a rectangular duct in the presence of a non-uniform transverse magnetic field

) flow in a corrugated channel under a constantheat flux boundary condition have been reported. The thermal behavior of the flow isinvestigated numerically using a two-phase mixture model and control volume tech-nique. It is concluded that using a magnetic field with a negative gradient on ananofluid flow in corrugated channels can be proposed as a suitable method to achievehigher heat transfer performance and augment the heat transfer coefficient and alsoreduces the wall temperature. This method can lead to the design of more compactheat exchangers. © 2013 Wiley Periodicals, Inc. Heat Trans Asian Res, 43(1): 80–92,2014; Published online 21 May 2013 in Wiley Online Library (wileyonlineli-brary.com/journal/htj). DOI 10.1002/htj.21060

Hydrothermal Behavior of a Ferrofluid in a Corrugated Channel in the Presence of a Magnetic Field

• Performance of helically finned latent heat thermal energy storage (LHTES) system is investigated. • Helically finned LHTES system is compared with straightly finned LHTES system. • Melting time of the PCM is reduced using helically finned LHTES system. • Both transverse convection and longitudinal convection play role for the helically finned LHTES system. • Existence of helical fin causes helicity of the molten PCM and formation of the vorticities. This paper is focused on the enhancement of the thermal performance of a vertically oriented shell and tube latent heat thermal energy storage (LHTES) system by using helical fins. In order to see the improvement made by using the helical fin in a LHTES unit, the performance of the helically finned LHTES system has been compared with those of axially finned LHTES system, and no finned LHTES system. The length of the helical fin in the helically finned LHTES system is considered equal to the total length of the four axial fins used in the axially finned LHTES system and the net volume of the PCM is supposed to be identical for all studied cases. Three different temperatures of 345 K, 355 K, 365 K have been considered for the inner tube wall. Results revealed that for the helically finned TESS, the total melting time of the PCM can be reduced up to 18.25%, 21.5% and 16.75% in comparison with axially finned LHTES system for the inner tube wall temperatures of 345, 355 and 365 K, respectively. The presence of a helical fin causes the penetration of the heat into the core of the PCM inside the container and the motion of the molten PCM will be affected by the result of the buoyancy forces and the centrifugal force. Thus, there will be both transverse convection and longitudinal convection for the helically finned LHTES system. Besides, for the helically finned LHTES system, the PCM receives the needed heat for its full melting (charging) in less time compared to the axially finned LHTES system. This is due to the helicity of the molten PCM and also the formation of the vorticities due to the existence of the helical fin which contributes to deeper penetration of the heat and melt front. 

Numerical investigation of using helical fins for the enhancement of the charging process of a latent heat thermal energy storage system

In this study, the subcooled boiling heat transfer of a Fe3O4/water magnetic nanofluid flowing through a vertical tube has been investigated experimentally in the presence and absence of a magnetic ...

Experimental study of the subcooled flow boiling heat transfer of magnetic nanofluid in a vertical tube under magnetic field

An experimental study of the subcooled boiling heat transfer of axial and swirling upward flows inside vertical mini annular gaps was conducted using deionized water. The subcooled boiling heat transfer coefficients and the boiling curves of the flow inside mini annular gaps with different gap sizes have been investigated. The experimental results both for the single phase heat transfer and subcooled boiling heat transfer inside mini annular gaps showed very good agreement with correlations in the literature. The results showed that the subcooled boiling heat transfer coefficient for a given heat flux increases as the size of the annular gap is decreased. The maximum wall superheat is also influenced negligibly by mass flux. Furthermore, the effects of swirl flow by using spring insets inside the mini annuli on the single phase and subcooled boiling heat transfer have been studied. The results showed that the single phase and subcooled boiling heat transfer coefficients are increased by having swirl flow inside mini annuli using spring inserts. The obtained results also showed that the heat transfer enhancement by having swirl flow inside the annuli using spring inserts decreases as the applied heat flux is increased in the subcooled boiling heat transfer region.

https://jafmonline.net/JournalArchive/download?file_ID=44266&issue_ID=246

S. Ahangar Zonouzi

Papers

Numerical study of the ferrofluid flow and heat transfer through a rectangular duct in the presence of a non-uniform transverse magnetic field

Hydrothermal Behavior of a Ferrofluid in a Corrugated Channel in the Presence of a Magnetic Field

Numerical investigation of using helical fins for the enhancement of the charging process of a latent heat thermal energy storage system

Experimental study of the subcooled flow boiling heat transfer of magnetic nanofluid in a vertical tube under magnetic field

Experimental Study of Subcooled Boiling Heat Transfer of Axial and Swirling Flows inside Mini Annular Gaps